Title :Effects of post clearing methods-on soil properties and
crop production
Experiment # : 1107
Researchers : Fahmuddin Agus, Michael K. Wade, Jusuf
Prawirasumantri
Objectives : To examine the effects of burning, tilling and
liming on a newly cleared Ultisol
To examine the interaction between burning and
liming
Soil : Clayey, Kaolinitic, Isohyperthermic QOrtehoxi:
Iropgdult. This is a newly cleared selected cut-
primary forest. Cleared in August 1984 by using
chain saw for slashing and human labor for
windrowing and clearing
Exp. design : Strip factorial plot design with 3 replications,
sub-sub plot of 48 m2. Main plots 3 burning
methods: No burn, one time burn, and two times
burn. Sub-plots tilling methods: No till and
minimum tillage. Sub-sub-plots lime rates:
equivalent to 0 and 1.5 me exchangeable Al.
Crop history : Soybean of Wilis variety was planted on December
22, 1984. Base fertilization (kg/ha) -100 urea,
100 TSP ( critical level ), and 100 KCL
Subjected to severe drought at flowering stage
and to worm damage at pod filling stage.
Sevin had been used several times to control insect
damages. Harvest, which was done on March 20,
1985, was relatively very low.
Results : Burning (one time or two times) gave highly
significant grain yield increase significant aluminum
saturation decrease, and significant pH increase over no burn
treatment. Liming gave highly significant increase in pH,
significant increase in Ca + Mg and highly significant decrease in
exchangeable aluminum Liming also gave significant yield
increase on the no burned and on one time burned plots. However
this increase was not seen on the twice burned plot. Tilling gave
significantly lower grain yield and the tilled plot had
significantly lower aluminum saturation. The 1 ime by burn
interaction for aluminum saturation was not significant, ie.
liming reduced aluminum saturation at all burn levels. There was
also no significant interaction on yield nor other soil
properties measured. Physical properties such as total pore
space, drainage pores, bulk density, and moisture content were
not affected by treatment. So far other soil properties such as
nitrogen, organic matter, etc, have not been completed yet.